Paleo- and Mesoproterozoic Complexes of the Ulutau Terrane (Central Kazakhstan): Structure, Age Substantiation, and Position in the Nuna Supercontinent

The article presents the results of study and substantiating the age (SHRIMP II, LA-ICP-MS) of Paleo- and Mesoproterozoic sedimentary and volcanosedimentary complexes of the Ulutau Terrane to west of Central Kazakhstan. Paleoproterozoic formations are represented by quartzites and schists of the Kumola Formation with a maximum sedimentation age 2.03 Ga. These formations, including the terrigenous strata of the Chuy–Kendyktas and Issyk-Kul terranes, mark the oldest stage of accumulation of mature sedimentary strata in the western part of the Central Asian belt, associated with the opening of rift basins within the Nuna Supercontinent during the post-collisional stretching stage. The Mesoproterozoic formations include the bimodal volcanic-sedimentary association of the Zhiide series (~1326–1367 Ma), which is associated with the Ectasian stage of rift magmatism that accompanied the breakup of the Nuna supercontinent. The data obtained suggest that in the Paleo- and Mesoproterozoic, the Ulutau Terrane, the Tarim Craton, and the Yangtze Craton had a similar evolution related to intraplate tectonomagmatic processes in the western and northwestern parts of the Nuna Supercontinent.